In a typical cellular wireless communication system, an area is divided geographically into a number of cells and cell sectors, each defined by a radio frequency (RF) radiation pattern from a respective base station antenna. The base station antennae in the cells may then be coupled with a base station controller, which may then be coupled with a switch or gateway that provides connectivity with a transport network such as the public switched telephone network (PSTN) or the Internet. When a mobile station, such as a cellular telephone, pager, or wirelessly-equipped computer, is positioned in a cell, the mobile station communicates via an RF air interface with the base station antennae of a cell. Consequently, a communication path can be established between the mobile station and the transport network, via the air interface, the base station, the base station controller, and the switch or gateway.
Further, in some wireless communication systems, multiple base stations are connected with a common base station controller, and multiple base stations are connected with a common switch or gateway. Each base station controller may then manage air interface resources for multiple wireless coverage areas (e.g., multiple cells and sectors), by performing functions such as assigning air interface traffic channels for use by mobile stations in the coverage areas and orchestrating handoff of calls between coverage areas. In turn, a switch and/or gateway may control one or more base station controllers and generally control wireless communications, by performing functions such as receiving and processing call requests, instructing base station controllers when to assign traffic channels, paging mobile stations, and managing handoff of calls between base station controllers.
In general, air interface communications in each sector (or other such coverage area) of a cellular wireless communication system can be encoded or carried in a manner that distinguishes the communications in that sector from communications in adjacent sectors. For example, in a Code Division Multiple Access (CDMA) system, each sector has a respective pseudo-random noise offset or “PN offset” that is used to encode or modulate air interface communications in the sector distinctly from those in adjacent sectors. Analogously, in other air interface protocols, communications in one sector may be distinguished from those in other sectors by frequency, time, and/or various other parameters.
Each sector may define an air interface “access channel” on which mobile stations can send “access probes” seeking to originate calls (e.g., voice calls, data sessions, and/or other “calls”) or seeking to register their presence in the sector. Further, each sector may define an air interface “paging channel” on which the serving base station can page a mobile station. For example, paging channel may be used to send access probe acknowledgements and traffic channel assignment messages to served mobile stations. The paging channel also defines timeslots in which the base station can send various messages to particular mobile stations. For instance, if an access probe is received from one mobile station seeking to connect to a second mobile station, the base station may send a page via the paging channel to notify the second mobile station of the incoming call.
If a base station has numerous such messages to send, however, the paging channel can become congested, which may delay call setup or even result in a page not reaching the intended mobile station. Accordingly, in a further aspect of existing CDMA access networks, base station commonly group a certain number of pages (that are typically intended for different mobile stations) into a common page message for transmission via the paging channel. Furthermore, to conserve bandwidth, and so that more pages can be transmitted per timeslot, each page in a page message may be concatenated.